Allergic rhinitis is a common illness suffered among US Veterans. Despite the availability of medications, many patients fail to get adequate control of symptoms especially in high pollutant areas. Southern California air pollutants, like diesel exhaust particles may act as adjuvants to allergens leading to an exaggerated allergic response in certain individuals. These individuals may lack adequate Glutathione transferase activity; necessary to protect cells against pollutant induced oxidative stress. Sulforaphane has been shown to protect against oxidative stress. We hypothesize consumption of foods containing high levels of sulforaphane are beneficial to US Veterans with GST deficiencies suffering from allergic rhinitis. In our preliminary data, we discovered administration of broccoli sprout extract rich in sulforaphane leads to diminished nasal inflammatory reaction brought on by diesel exhaust particles though did not have sufficient patient numbers to prove an association with GST deficiency. We propose a 3 week randomized clinical trial comparing broccoli sprout extract consumption with nasal corticosteroid administration after subjects with allergic rhinitis undergo a Timothy, Bermuda or Johnson grass nasal challenge. In Aims 1 and 2, we will compare clinical (nasal symptom scores and peak nasal inspiratory flows) and laboratory (inflammatory cytokines, eosinophil cationic protein, tryptase) measurements between four groups: nasal corticosteroid, broccoli sprout extract, nasal corticosteroid plus broccoli sprout extract, and placebo. Aim 3 focuses on exploratory genetic analysis of the 3 glutathione S-transferase (GST) genes to determine if correlations exist between the inability to produce GST enzyme and the response to broccoli sprout extract. At the conclusion of this study, we will gain further knowledge of which patients benefit from anti-oxidant nutritional supplementation in treating allergic rhinitis.